LMX2571: The output power of RFOUT_TX

Ricardo Li

Part Number: LMX2571

Dears,

Our customer is using LMX2571 in his application. Now, he have a question about the output power of RFOUT_TX. The frequency of input signal is 13MHz, the output frequency is 72.1-75.44MHz. He want to get a 0 dBm output power, the configs of LMX2571 are as following : output type is Push-Pull, RFOUT_TX enable, RFOUT_RX disable, the low five bits of register of R24 and R8 are all 1. Does this configs could get a 0 dBm output power? If not, how to get a 0 dBm output power?

The customer detected the output power, it's about -3dBm, the input and output as follows:

Thanks for your help in advance.

Regards,

Ricardo

over 7 years ago

0 Simon Damphousse over 7 years ago

TI__Expert 5370 points

Dear Ricardo,

let me check the power level you should expect.

Regards, Simon.

0 Simon Damphousse over 7 years ago in reply to Simon Damphousse

TI__Expert 5370 points

Dear Ricardo,

I connected the same output labelled "Tx". I used a male2male SMA and connected the PCB directly into a spectrum analyzer. The output power I measure at max output setting is 1.4 dBm at 75 MHz.

I am not sure you are getting 4 dB+ down from my measurement. Cable is unlikely to be the cause at 75 HMz.

could you change cable length or just try a male2male connector.

Regards, Simon.

0 Ricardo Li over 7 years ago in reply to Simon Damphousse

TI__Intellectual 1045 points

Dear Simon,

OK, I know. Thank you for you help, I will tell the customer.

Regards,
Ricardo

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LMX2571: The output power of RFOUT_TX